In the manufacture of automobiles and many other devices, wall structures used in the device include a frame covered with a skin or panel. Frequently, a further panel our outer covering is applied thereover. The internal space of a wall may contain a variety of structures and apparatuses to which access is required during manufacture and assembly. Further, it is sometimes necessary that an opening be provided in panels for hand or tool access to fasteners and the like. Often, after assembly is complete, there is no further need for access through such openings in panels.
It is desirable that assembly access openings be closed for both appearance and function. An opening in a panel provides a path for contaminants to pas from one side of the panel to the other side of the panel, potentially fouling or damaging components. Moisture from rain, snow, vehicle washings and the like can accumulate within a wall structure, causing corrosion from the inside out. Therefore, it is desirable not only to close such openings but also to seal the opening in a watertight manner.
Various plug structures have been used to seal panel openings, some with more success than others. In one known arrangement, a body shaped to fill the opening is provided with a thermal adhesive on a flange surrounding the body. The adhesive is activated to create a watertight bond of the plug to the panel when the panel is placed in a cure oven after painting. In some instances, a problem is experienced in retaining the plug in proper position during the necessary handling and movement of the panels after the panel has been plugged and while the panel is being painted and moved into the cure oven. Various mechanical fasteners have been used to retain the plug in proper location to close the hole. Such fasteners can add considerable cost and may require a time consuming procedure for fastening.
What is needed in the art is a watertight plug that is inexpensive, reliable, easy to install and secure, even before final bonding.